An intrinsically safe battery pack may include a built-in safety circuit to prevent arcing during installation and/or removal of the battery pack. One such battery pack includes a safety circuit that de-energizes terminals of the battery pack when an operator turns off the unit powered by the battery pack. However, if the operator fails to turn off the unit prior to removing or installing the battery pack, the operator runs the risk of arcing which may have catastrophic results in certain hazardous environments (e.g. an oil refinery).
In another battery pack, a safety circuit introduces a time delay between detecting an applied load to the battery pack and energizing the terminals of the battery pack. When the operator turns the unit on, the battery pack energizes the terminals after a time delay. The time delay permits, the battery pack to be installed in a unit that is turned on without an arcing potential. Removal, however, still runs the risk of arcing if the unit is not turned off.
Installation of battery packs in wireless sensors of a sensor networks may present additional obstacles. Wireless sensors typically do not have an on/off switch. As such, the operator commonly is unable to turn off the wireless sensor prior to installation and/or removal of a battery pack. Moreover, the operator commonly can not wait until the battery of the battery pack is exhausted prior to replacing the battery pack.